In Caverns Below by Stanton A. Coblentz — Read

It was what was known to the chalk-faces as the "mid-sleep. " The lights of the public galleries had been dimmed to a slumberous dullness; the lamps of the houses had been extinguished, the ventilating currents were turned low; and only an occasional belated wayfarer or military guard, darting through the deserted thoroughfares an his little "scootscoot," gave proof that life still went on in the land of Wu.

At this silent hour, when the house doors stared in black, almost invisible lines along the empty passageways, a figure might have been seen stealthily emerging from one of the doorways and slinking off down a narrow side-corridor. Had one followed in his footsteps, one would have observed how he wound and twisted through a multitude of lanes, sometimes pausing as if uncertain of his course, sometimes huddling in fright in some dismal alley while a "scootscoot" glided past, but gradually making his way upward amid the intricacy of the Underworld.